Author: Endaf Griffiths. 

Series: Cyfres yr Hambons.

Who can solve the mystery of the missing sheep? Sheep are going missing from the fields - and no-one knows how or why. As the local farmers all disagree with each other about how to deal with this problem, three friends - Llew, Ianto ac Efa - decide to investigate the matter themselves. What is happening to the sheep? Are they being stolen by thieves? Or are they being swallowed up by the earth?. 

Awdur: Endaf Griffiths. 

Cyfres yr Hambons.

Pwy all ddatrys dirgelwch y defaid coll? Mae defaid yn diflannu o'r caeau - heb neb yn gwybod sut na pham. Wrth i ffermwyr yr ardal anghytuno â'i gilydd ar sut i ddelio â'r dirgelwch hwn, mae tri ffrind - Llew, Ianto ac Efa - yn penderfynu ymchwilio i'r mater eu hunain. Beth sy'n digwydd i'r defaid? Ydyn nhw'n cael eu dwyn gan ladron? Neu eu llyncu'n gyfan gwbl gan y Ddaear?